vikasp99
A report of a government survey concluded that Center City was among the ten cities in the nation with the highest dropout rate from its schools. The survey data were obtained by asking all city residents over the age of 19 whether they were high school graduates and computing the proportion who were not. A city school official objected that the result did not seem accurate according to the school's figures.
The school official can most properly criticize the reasoning by which the survey report reached its result for failure to do which one of the following?
(A) take into account instances of respondent's dropping out that occurred before the respondents reached high school.
(B) ask residents whether they had completed their high school work in fewer than the usual number of years.
(C) distinguish between residents who had attended the city's schools and those who had received their schooling elsewhere.
(D) predict the effect of the information contained in the report on future high school dropout rates for the city.
(E) consider whether a diploma from the city's high schools signaled the same level of achievement over time.
Source : LSAT PrepTest 20 Q#15
Survey - Ask all city residents over the age of 19 whether they were high school graduates and computing the proportion who were not.
(If the city had 100 people, they were all asked whether they completed high school. Say 40 said they did not and 60 did.)
Conclusion:
Center City was among the ten cities in the nation with the highest dropout rate from its schools
(It was concluded that the school dropout rate for the city is 40%)
(A) take into account instances of respondent's dropping out that occurred before the respondents reached high school.It does take into account all school dropouts. Anyone who drops out at any time before completing high school is a school dropout. Whether they dropped out in elementary, middle or high school - anyone who did not complete high school is a school dropout. So they have all been accounted for. At exactly which level they dropped out is irrelevant.
(B) ask residents whether they had completed their high school work in fewer than the usual number of years.Time taken to complete high school work is irrelevant.
(C) distinguish between residents who had attended the city's schools and those who had received their schooling elsewhere.Exactly. What if dropout rate is much lower in this city but much higher in a neighboring city and people who study in the neighboring city come here for jobs?
Of the 100 people:
Say 80 people did their schooling from this city and only 20 dropped out (a 25% dropout rate)
So 20 people did their schooling from a neighboring city and all of them dropped out. These people also get counted as dropouts from Center City's schools though that is not true.
Hence the survey needed to distinguish between residents who had attended the city's schools and those who had received their schooling elsewhere.
(D) predict the effect of the information contained in the report on future high school dropout rates for the city. Future rates are irrelevant.
(E) consider whether a diploma from the city's high schools signaled the same level of achievement over time.The point is whether they completed or not. Whether completion has the same value over time is irrelevant.
Answer (C)